My 90 suburban is blowing the ecm1 fuse as soon as the key is turned to the start position. This fuse is the power feed for the ecm. I have unplugged the ecm, fuel pump relay, and any thing else I can think of and it still blows this fuse. Normally I wouldn't worry about it but this one has to work in order for the truck to start. If anyone can think of something I may have overlooked I thank you in advance. Rob.